Oscillating drive electromagnetic motor system



Jan. 14, 1964 R. w. REICH 3,118,098

OSCILLATING DRIVE ELECTROMAGNETIC MOTOR SYSTEM Filed June 6, 1958 RZ -IO S J Fig.5

\ 2 INVENTOR ROBERT WALTER RE/CH F- 4 1/ ATTORNEY5 United States Patent3,1itl,tl@8 OCILLATING DRIVE ELEtITilGMAGNETlC MOTOR SYSTEM RobertWalter Reich, Freiburg im lireisgau, Germany, assignor to.laln'esuhren-Fahrilr G.n1.lJ.H., Au. Schatz & Solute, Tribes-g, BlackForest, Germany Filed June 6, 1%8, Ser. No. 740,496 Claims priority,application (Germany June 7, 1957 9 Claims. (til. 318-128) The presentinvention relates to electronic clocks. More in particular, the presentinvention relates to an i-mpelling system for electronic pendulumclocks.

It is known to construct electronic clocks the impelling system of whichcomprises separate exciting and driving coils. These constructions callfor the use of bar magnets entering into the coils. An impulse producedin the exciting coil is amplified by a transistor and then used as adriving impulse in the driving coil.

This construction is undesirable and sulfers from a number ofdisadvantages. The coils must have a certain minimum size tor producingthe exciting impulse and the impulse for driving the pendulum. The coilscannot be entirely covered as the bar magnets must be allowed to enterthe coils. A very delicate and difficult adjustment is required in orderto prevent excessive oscillations of the pendulum and the assembly ofthe individual clocks is thus very complicated and time-consuming. It isa further disadvantage that the driving impulse impels the pendulum inone direction only, the motion of the pendulum in the other directionbeing the result of free oscillation. Only after the end of this freeoscillation and upon reversal of the pendulum the exciting coil producesthe necessary impulse for controlling the driving coil. The two coilshave to be separate as their coupling would result in a self-excitedoscillation of the system in view of the fact that the driving coil mustbe disposed in the emitter or collector circuit of the transistor andthe exciting coil must be provided between the base and the emitter.This stops the further operation of the clock and the exciting anddriving impulses cannot perform their desired functions.

Although this danger is avoided in the known constructions with separatecoils there is yet another disadvantage resulting from the fact that theexciting coils have a small cross section of the wire but a great numberof windings and therefore a very high DC. resistance in the order ofseveral thousand ohms. As this resistance is arranged between theemitter and the base of the transistor it produces a negative voltage atthe base which, in turn, results in a permanent current which is atleast equal to the necessary driving current. The total currentconsumption or" the impeiling system is therefore quite considerable andrenders the entire electronic clock uneconomical in operation. Aconventional dry cell battery will have to be replaced after a veryshort period of operation, although only a small fraction of the currentconsumption has actually been used for producing the driving impulseswhich are effective for very short intervals only.

It is an object of the present invention to provide an impelling systemfor electronic pendulum clocks, which operates extremely accuratelywithout requiring a difiicult adjustment of the exciting and drivingcoils.

It is another object or" the present invention to provide an impellingsystem for electronic pendulum clocks, whereby the pendulum is impelledand controlled in either one of its two senses of motion.

It is a further object of the present invention to provide an impellingsystem for electronic pendulum clocks, in which only the current usedfor creating the exciting and driving impulses is consumed and in whichthe current consumption is therefore greatly reduced.

Patented Jan. i l,

It is still another object of the present invention to provide animpelling system for electronic pendulum clocks, in which a self-excitedoscillation of the impelling system is prevented by simple and efieotivemeans.

it is yet another object of the present invention to provide animpelling system for electronic pendulum clocks, whose elements areadapted to be so disposed that the clock casing may have a pleasantappearance, and that the clock can be easily assembled as Well asrepaired.

It is a further object of the present invention to provide an impellingsystem for electronic pendulum clocks, which is self-starting.

These objects as well as further objects and advantages which Willbecome apparent as the description of the invention proceeds areachieved by the impelling system for electronic pendulum clocks of thepresent invention, comprising a current source, a pendulum, a permanentmagnet, and a driving coil and a transistor, and in which the permanentmagnet is mounted at the lowermost end of the pendulum, polarized in thedirection of the longitudinal axis of the pendulum, and wherein theexciting and driving coils are concentrically disposed relative to eachother and with their common center below the resting point of thependulum. Furthermore, the exciting coil is D.C.-s-hort-circuited via ahighly blocking diode connected with the emitter or the positive pole ofthe current source and the base of the transistor.

T he invention will be more fully appreciated upon the followingdetailed description of the accompanying drawings, wherein FIGURE 1 is aschematic view of the impelling system for the electronic pendulum clockof the present invention;

FIGURE 2 is a schematic view of the impelling system for an electronicrotary pendulum clock of the invention;

FEGURE 3 is a wiring diagram of the impelling system for an electronicpendulum clocl: of the present invention;

FIGURE 4 is a schematic view in combination with a wiring diagram of theimpelling system for an electronic pendulum clock of the presentinvention;

FEGURE 5 is a Wiring diagram of a preferred embodiment of the impellingsystem for an electronic pendulum clock of the invention.

Turning now to the drawings somewhat more in particular, the drivingcoil i. and the exciting coil. 2 are disposed concentrically Withrespect to each other, the interior coil 1 being the driving coil andthe exterior coil 2 being the exciting coil. The two coils are posedbelow the plate 4 of the electronic pendulum clock in the foot of theclock and are therefore not visible. The center of the two coils issituated exactly below the vertically disposed pendulum 5 or below thecenter of the rotary pendulum with regard to the resting position of thelatter; the concentric axis or" the coils is in alignment with thelongitudinal axis of the pendulum 5 or the longitudinal axis of rotationof the rotary pendulum while the pendulum 5 or Be is at rest. At thelowermost end of the pendulum 55 or in the center of the rotary pendulumthere is provided the permanent magnet 3 which contrary to knownconstructions is so disposed that its re spective poles are locatedparallel to the respective longitudinal axes of the pendulum 5 or therotary pendulum in the resting position of the pendulum 5' or do a northor south pole is disposed directly above the center of the twoconcentric coils l and 22. Furthermore, the external diameter of thepermanent magnet 3 is identical to the internal diameter of the excitingcoil 2. Consequently, an impulse is produced in the exciting coil 2 assoon as the pendulum is or the rotary pendulum leaves its restingposition.

The electrical exciter system and circuit suitable for exc electricclock is illu in FIG. 3. T. 1e driver co ected in series circuitconnection w h n l is the cxciter co base electrode the collector thedriver coil base B of tra exciter coil interconnects electro: e E oftransistor 16, l ich includes a battery 7 and rode ii is connectedbetween the and t 've terminal of the source one short circ "ing the Anadjust le sister 2 i s ries t connection h diode erl above operates asfollows.

entiulum with its perma- -i-. down above coils l and 2 and no volta e isinduced in the exeiter coil 2 consequently the em'.ter base oftransistor lr'l is biased to zero or itter current collector ct ant sdrawn from the battery. Thus, o y the negli le collector leakage currentilows through the dr er coil If now the pendulum deflects towards the t,the flu penetrating coil by a negative voltage is of transistor 16 rcurrent thus opens collects the collector current flows driver col 1. Itis to be observed that the co r nt r'lows only after the voltage inducedin coil 2 exceed d a certain minimum magnitude which The two coils l and2 are magnetically coupled ti, 1 the permanent magnet 33, thus givingcause to a feed-back effect which in turn means that tlcse two coilsloge er with the transistor and the battery form 2 g oscillator. Duringthe opening of the em er-base of transistor 15 a plurality of s are setup in the driver coil 1. The frequency of tl 'llation amounts to about100-) to 10600 c.p.s. and ms is substant' ly above the frequency of thepenienal means, such as the diode ll, freely regardless of any furtherint ma" e 23. This is true even rial half waves of these oscillavercoil, raving a direction positive These oscillations are initive wavesof the voltage in- The positive oscillation pulses as they are gsimultaneously in the driver coil produce a .ctic field only in o cdirection which repels the permanent magnet 3 and mus increases the de-At a pr determ led time the the permanent magnet 3 returns and a in theexci'ter coil 2. The voltage eby renders the base of transistor more itrespect to the emitter and trus causes cut-oil however, shortand bringsthe effective .hout ad ct to the e ate-cl only during duced in the e."

positive Wll of the collector current. circuits the positive base vo -cresistance or" e er-iciter coil to zero in this Therefore, theoscillator is cut oil at any time because it is an effect presentblocking oscillator clue to the ion of diode Alth ugh the magnet 3enters again into the effective area of the excit r coil, oscillationsof transistor system effectively prevented and the collector current iscut off until the magnet 3 hangs directly above the c er line o thecoils l and Z. The permanent ma net 3 now. of course, continues to movefor a dfltl :1 toward the left giving rise to the i .Licernent ofanother negative pulse in exciter coil 2 which in turn produces anotherset of osc'llations in driver coil ll. Consequently, another repellingis induced by driver coil 2 a the magnet 3 is pusher: towards the left.Upon re urning of magnet 3 exciter coil again induces a p e voltage onthe base of a transistor 1% which again is short-circuited and theoscillations disappear in driver coil 1. As it can be seen from theforeeach com ete cycle or the pendulum, two

l't VJlll be of particular advantage to insert an adjustable resistance13 into the diode circuit for exactly controlling the es voltage of thebase. This makes it possible to exactly adjust the closed circuitcurrent to zero and also to control the intensity of the excitingimpulse. in view of the fact that t e intensity of the exciting impulseconditions t.e amp utle and the number of the oscillations theresistance 13 can be used to adjust tr e accuracy 0:? operation of theclock. The short-circuiting of the DC. resistance of the exciting coilwill also result in a perfect temperature compensation of thetransistor, as the emitter and base voltages are identical or the basevoltage is even higher than the emitter voltage.

The impelling system of the present invention is also applicable topendulum or rotary pendulum clocks of comparatively great size. If thetransistor 1% shown in FIGURES 3 and 4- is not suilicient to impel thependulum a system can be used as shown in FlGURE 5. in addition to afirst transistor 1% a second, power transistor T5 is added. The firsttransistor ltla is connected in the same manner as is transistor inPEGURE 3; there are again two coils la, s a battery 7a, a highlyblocking dlode Ella and ad ustable resistance 13 The second transistori5 is connected with its base directly to the emitter E or" the firsttransistor The variations in voltage at the emitter correspond to theexc g impulses and so control the power transistor T5. The 'riving coilor several driving coils are inserted in the collector circuit C of thepower transistor. The closed circuit current is zero while the excit .igimpulse is am ed by the transistors and the driving impulse of thenecessary inten ity is obtained.

It is also possible to provide m ans enabling a selfstarting ope tion oftile pendulum clock. These means may consist of a small permanent magnet17 constituting the core of the concentric coils l and 2. The polarityof this small magnet 17 is so adapted that a small repelling force isexercised upon the magnet 3 in the pendulum. This small repelling forceis sufficient to move the pendulum from its resting position and themovement of t re pendulum immediately creates an impulse in the excitingcoil and thereby the operation of the clock is started.

The impelling system for electronic pendulum clocks of the presentinvention offers considerable advantages comeared with the knownconstructions. Conary to the wn art the pendulum is impelled in bothdirections of its movement and. thereby the clock operates with a finelyadjusted accuracy which was heretofore unknown.

The permanent magnet 5 can be provided in any pendulum so as to beinvisible. Since the entire coil combination is compos in the foot ofthe clock casing 6 it is also invisible a it is possible to employcasings of a particularly pleasant design. Furthermore, the supply wirescan also be provided below the foot of the clock and the clock istherefore easy to repair. The entire mecha al .vorlis is with the dial 5and the pendulum 5 or 5:: with the magnet 3 can therefore be removedwith the coils and the electric supply Wires below the plate 4 ainingundisturbed. The power source can also be sposed below the plate 4. Apermanent current is non-existent and the only load applied to the powersource is the small impulses used for the exciting coil. Consequently, amuch smaller power source can used in known constructions. Instead of adry cell battery 2. very small accumulator can be used in combinationwith a recharging circuit.

lit will be understood that this invention is susceptible tomodification in order to adapt it to different usages and conditions.and, accordingly, it is desired to comprehend such modifications withinthis invention as may fall within the scope of the appended claims.

What I claim is: l. in an electronic clock, an impelling systemcomprising: a pendulum, a permanent ma net provided in the lower portionof said pendulum with its respective poles extending in the direction ofthe longitudinal axis of said pendulum, an exciting coil, a driving coildisposed inside of and concentric with said exciting coil, said excitingcoil and said driving coil being located below said permanent magnetwith their common axis being in alignment with the longitudinal axis ofsaid pendulum while the latter is at rest; a DC. voltage source; atransistor having base, emitter, and collector electrodes, said excitingcoil being connected to said base and said emitter electrode; means forcompleting a series circuit connection of said voltage source, saiddriving coil and the emitter-collector path of said transistor; and arectifying diode connected in parallel to the base-emitter circuit andof a forward direction opposite to the forward direction of the emitterelectrode.

2. In an electronic clock, an impelling system comprising a pendulum, apermanent magnet provided in the slower portion of said pendulum withits respective poles extending in the direction of the longitudinal axisof said pendulum, an exciting coil, a driving coil. disposed inside ofand concentric with said exciting coil, said exciting coil and saiddriving coil being located below said permanent magnet with their commonaxis being in alignment with the longitudinal axis of said pendulumwhile the latter is at rest; a DC. voltage source, a transistor havingbase, emitter and collector electrodes, said base and emitter electrodesbeing connected to one of said coils, the emittercollector path of saidtransistor being connected to one of said coils and to said DC. voltagesource, a highly blocking diode havinn two electrodes and being con-.ected with one electrode to said base at such a polarity so as to blockbase current therefrom, said diode being connected with the other one ofits electrodes to said DC. voltage source so as to reversely bias saiddiode.

3. In an electronic clock, an impclling system comprising, a rotarypendulum, a permanent magnet provided in the lower portion of saidpendulum with its respective poles extending in the direction of thelongitudinal axis of rotation of said rotary pendulum, an exciting coil,a driving coil disposed inside of and concentric with said excitingcoil, said exciting coil and said driving coil being located below saidpermanent magnet with their common axis being in alignment with thelongitudinal axis of ro-- tation of said rotary pendulum while thelatter is at rest, a DC. voltage source; a transistor having base,emitter and collector electrodes, said exciting coil being connected tosaid base and said emitter electrode, means for completing a seriescircuit connection of said voltage source, said driving coil and theemitter-collector path of said transmitter; a highly blocking diodelikewise connected to said emitter and base electrodes at such apolarity opposite to the direction of the current in said baseelectrode.

4. In an electronic clock, an impelling system comprising a DC. voltagesource, a pendulum, a permanent magnet provided in the lower portion ofsaid pendulum with its respective poles extending in the direction ofthe longitudinal axis of said pendulum, an exciting coil, a

drivin coil disposed inside of and concentric with said exciting coil,said exciting coil and said driving coil being located below saidpermanent magnet with their common axis being in alignment with thelongitudinal axis of said pendulum while the latter is at rest, a firsttransistor having base, emitter, and collector electrodes, said base andemitter electrodes being connected to said exciting coil, 21 secondpower transistor also having base, emitter and collector electrodes andbeing connected with its base to the emitter of said first transistor,said driving coil interconnecting the collector of said power transistorand one pole of said voltage source, the collector of said firtransistor being also connected to that pole, means for connecting theemitter electrodes of said transistors to the other pole of said voltagesource, and a highly blocking diode connected between the base electrodeof said first transistor and the last mentioned pole of said voltagesource and a direction reverse to the base-current direction.

5. In an electronic clock as described in claim 2, there being a clockcasing with a base plate, said pendulum being suspended in said clockcasing above said base plate, said exciting coil and said driving coilbeing located below said plate.

6. In an electronic clock, an impelling system as described in claim 2,with the internal diameter of said exciting coil being identical to theexternal diameter of said permanent magnet.

7. In an electronic clock, an impelling system as described in claim 2,further comprising an adjustable resistance connected to said diode.

8. In an electronic clock, an impelling system as described in claim 2,further comprising a permanent magnet core forming the core of saidexciting and driving coils.

9. In an electronic clock, the combination which comprises: a pendulum,a permanent magnet provided in the lower portion of said pendulum withits respective poles extending in the direction of the longitudinal axisof said pendulum, an exciting coil, and a driving coil disposed insideof and concentric with said exciting coil, said exciting and drivingcoils being located below said permanent magnet with the common axis ofsaid coils being in alignment with the longitudinal axis of saidpendulum while the latter is at rest.

References Cited in the tile of this patent UNITED STATES PATENT

1. IN AN ELECTRONIC CLOCK, AN IMPELLING SYSTEM COMPRISING: A PENDULUM, APERMANENT MAGNET PROVIDED IN THE LOWER PORTION OF SAID PENDULUM WITH ITSRESPECTIVE POLES EXTENDING IN THE DIRECTION OF THE LONGITUDINAL AXIS OFSAID PENDULUM, AN EXCITING COIL, A DRIVING COIL DISPOSED INSIDE OF ANDCONCENTRIC WITH SAID EXCITING COIL, SAID EXCITING COIL AND SAID DRIVINGCOIL BEING LOCATED BELOW SAID PERMANENT MAGNET WITH THEIR COMMON AXISBEING IN ALIGNMENT WITH THE LONGITUDINAL AXIS OF SAID PENDULUM WHILE THELATTER IS AT REST; A D.C. VOLTAGE SOURCE; A TRANSISTOR HAVING BASE,EMITTER, AND COLLECTOR ELECTRODES, SAID EXCITING COIL BEING CONNECTED TOSAID BASE AND SAID EMITTER ELECTRODE; MEANS FOR COMPLETING A SERIESCIRCUIT CONNECTION OF SAID VOLTAGE SOURCE, SAID DRIVING COIL AND THEEMITTER-COLLECTOR PATH OF SAID TRANSISTOR; AND A RECTIFYING DIODECONNECTED IN PARALLEL TO THE BASE-EMITTER CIRCUIT AND OF A FORWARDDIRECTION OPPOSITE TO THE FORWARD DIRECTION OF THE EMITTER ELECTRODE.